Postfix legacy releases 2.7.3, 2.6.9, 2.5.12 and 2.4.16

Postfix legacy releases 2.7.3, 2.6.9, 2.5.12 and 2.4.16 are
available. These releases contain a fix for CVE-2011-0411 which
allows plaintext command injection with SMTP sessions over TLS.
This defect was introduced with Postfix version 2.2.

Note: CVE-2011-0411 is an issue only for the
minority of SMTP clients that actually verify server certificates.
Without server certificate verification, clients are always vulnerable
to man-in-the-middle attacks that allow attackers to inject plaintext
commands or responses into SMTP sessions, and more.

Fix to the local delivery agent: look up the "unextended"
address in the local aliases database, when that address has a
malformed address extension.

Fix to virtual alias expansion: report a tempfail error,
instead of silently ignoring recipients that exceed the
virtual_alias_expansion_limit or the virtual_alias_recursion_limit.

Fix for Solaris: the Postfix event engine was deaf for
SIGHUP and SIGALRM signals after the switch from select() to
/dev/poll. Symptoms were delayed "postfix reload" response, and
killed processes with watchdog timeout values under 100 seconds.

Fix for HP-UX: the Postfix event engine was deaf for SIGALRM
signals. Symptoms were killed processes with watchdog timeout
values under 100 seconds.

Fix for BSD-ish mkdir() to prevent maildir directories
from inheriting their group ownership from the parent directory.

Fix to the SMTP client: missing support for mail to
[ipv6:ipv6addr] address literal destinations.

Wietse Venema discovered the problem two weeks
before the Postfix 2.8 release, and silently fixed it pending further
investigation. While investigating the problem's scope and impact,
Victor Duchovni found that many other TLS applications were also
affected. At that point, CERT/CC was asked to coordinate with the
problem's resolution.